Dimpling a barrel

[tylerw02]

Some companies LOVE barrel fluting. There is good money in fluting.

But fact of the matter is, for everybody you find that is "pro" fluting, you're also going to find those against it.

So does this count as "proof"?

What about "fluting" a barrel?
Fluting is a service we neither offer nor recommend. If you have a Shilen barrel fluted, the warranty is void. Fluting a barrel can induce unrecoverable stresses that will encourage warping when heated and can also swell the bore dimensions, causing loose spots in the bore. A solid (un-fluted) barrel is more rigid than a fluted barrel of equal diameter. A fluted barrel is more rigid than a solid barrel of equal weight. All rifle barrels flex when fired. Accuracy requires that they simply flex the same and return the same each time they are fired, hence the requirement for a pillar bedded action and free floating barrel. The unrecoverable stresses that fluting can induce will cause the barrel to flex differently or not return from the flexing without cooling down a major amount. This is usually longer than a shooter has to wait for the next shot. The claim of the flutes helping to wick heat away faster is true, but the benefit of the flutes is not recognizable in this regard until the barrel is already too hot.
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Or why not talk to Mike? He GUARANTEES 1/4 MOA with factory ammunition from his rifles. Ask him what he has to say about fluting.

Tactical Operations, Inc.
433 North Camden Dr. 4th Fl. #239
Beverly Hills, Ca 90210
Phone 310 275-8797
Fax 323 933-3521
info@tacticaloperations.com

[Belmont31R]

Its my understanding there can be some negative reactions in some barrels to fluting...particularly barrels that were button rifled and then fluted. Button rifling basically smashes the metal up into the rest of the barrel to create the lands and grooves. That creates stress just like hammer forging does. If the barrel is not properly stress relieved, and then its fluted you get the weak/soft spots.


It doesn't appear to negatively affect many manufacturers...so to me it seems more like a process issue rather than fluting causes problems. If a barrel wasn't properly stress relieved then cutting away material reveals the stresses already there. It doesn't cause stress. If someone says removing material via cutting introduces stress than how do they even profile the barrel, thread the muzzle for a muzzle device or cut the crown, ect? A barrel goes through a lot of cutting. I have a hard time believing all that cutting doesn't introduce stress but dimpling or fluting does? That doesn't make any sense.


There are a lot of things company's do to make money. Doesn't mean they are selling snake oil. Its obviously physics that more surface areas means more rapid cooling. If you take two barrels of the same weight but different OD the one with the bigger OD is going to be more rigid.


Im sure some companies have had issues with it, but again, I think thats more of an issue with the process they used than there being a negative. People may also see taking an issue with having one barrel, cutting flutes, and then seeing a reduction in accuracy because you are weakening the barrel. Thats not the right way to look at it. The way to look at it is saying I want a 3lb barrel and make it as strong as possible. A 3lb barrel that was fluted or dimpled is going to be stronger than a 3lb barrel that is just a straight cut. If you want to take a 4lb barrel, and cut flutes in it bring the weight down to 3lbs then its not going to be as strong as a 4lb barrel left alone.


There are a lot of top notch companies out there making and using fluted barrels. Accuracy International is one of them, and they make some of the most premier military sniping rifles in the world. If you look at FN they make rifles with a 1/2MOA guarantee that are both fluted and hammer forged...two process which supposedly can introduce the most stress. So I think its how the barrel is treated and made rather that blanket saying doing X is going to be detrimental no matter what. By the logic of saying cutting flutes causes stress, again, how can you make any other cuts and not introduce stress as well?


I emailed Shilen with some questions. Ill post their response if/when I get one.

Some companies LOVE barrel fluting. There is good money in fluting.

But fact of the matter is, for everybody you find that is "pro" fluting, you're also going to find those against it.

So does this count as "proof"?



Or why not talk to Mike? He GUARANTEES 1/4 MOA with factory ammunition from his rifles. Ask him what he has to say about fluting.

Tactical Operations, Inc.
433 North Camden Dr. 4th Fl. #239
Beverly Hills, Ca 90210
Phone 310 275-8797
Fax 323 933-3521
info@tacticaloperations.com

[tylerw02]

Yet you've posted more hearsay, rather than any form of scientific evidence.

Fact of the matter is the only thing fluting does is remain expensive and reduce weight by a small margin.

As a fluting barrel with a greater OD is more rigid than a smaller profile barrel of the same weight, a non-fluted barrel with the same diameter is more rigid than than the fluted barrel.

Fluting is not some kind of miracle...and you concede that fluting improperly is detrimental, you'll find few companies flute the "right" way.

[Belmont31R]

Yet you've posted more hearsay, rather than any form of scientific evidence.

Fact of the matter is the only thing fluting does is remain expensive and reduce weight by a small margin.

As a fluting barrel with a greater OD is more rigid than a smaller profile barrel of the same weight, a non-fluted barrel with the same diameter is more rigid than than the fluted barrel.

Fluting is not some kind of miracle...and you concede that fluting improperly is detrimental, you'll find few companies flute the "right" way.

I said the same thing as you, and Im posting hearsay?


If you do anything wrong its possibly going to cause an issue. That doesn't mean fluting is inherently "bad". Using examples of something being done improperly as suggesting all examples no matter if done properly or not isn't exactly sound logic.


Im not debating the value of spending money to get a fluted barrel or buying a gun with a fluted barrel. All Im discussing is the physical value of doing such thing. I don't really care if someone thinks its worth it or not. Value is in the eye of the beholder.


I never said fluting is a miracle. Its simply a process that can yield certain results in a hunk of metal...such as making a stronger barrel of the same weight as a barrel that was not fluted. Like an I-Beam is stronger than just a tube of metal and has more surface area. If you don't think the process is worth the cost then thats up to you to decide. Doesn't take away from the benefits it can offer. Obviously quite a few top notch companies see the benefit in doing it.

[orionz06]

Like an I-Beam is stronger than just a tube of metal and has more surface area.

That is WAAAY too general. What was said above by Tyler was pretty accurate.

[Belmont31R]

That is WAAAY too general. What was said above by Tyler was pretty accurate.

Which is pretty much the same thing I have been saying.

[AEuropa]

I'd just like to point out that NO ONE has posted any actual data to support their position.

It cools faster? Ok, show me the numbers.
It causes stress? Ok, show me actual, real-world side effects that adversely affect accuracy, durability, or reliability.
It makes a barrel more stiff? Ok, show me the difference in deflection.

I'm all for hyperbolic arguments...they are what make the internet fun. But unless there's actual data being thrown around, then this is all merely conjecture and people are getting really heated over nothing.

- Alex

[sniperfrog]

Bill Sheehan set a 1000 yard benchrest world record with a barrel that he had fluted after he had already used it for half a season.

ADCO told me that fluting an 18" SPR barrel under the handguards would remove about 5 ounces.

[mbogo]

Barrels are 'individuals'. Dimple/flute 1000 barrels; accuracy-wise, some will be adversely affected, some will benefit, others will be unaffected.

If the weight savings are worth the risk of decreased accuracy, go for it.

mbogo

[Belmont31R]

I'd just like to point out that NO ONE has posted any actual data to support their position.

It cools faster? Ok, show me the numbers.
It causes stress? Ok, show me actual, real-world side effects that adversely affect accuracy, durability, or reliability.
It makes a barrel more stiff? Ok, show me the difference in deflection.

I'm all for hyperbolic arguments...they are what make the internet fun. But unless there's actual data being thrown around, then this is all merely conjecture and people are getting really heated over nothing.

- Alex

Type in google radiant heat transfer formulas. They take into account surface area in the calculation.


Fluting and dimpling increase the surface area therefore the rate of heat transfer to the atmosphere is going to increase.


Its the same concept as fins in a radiator (why they are called radiators actually). The greatly increased surface area in a radiator fin assembly transfers heat out of the solid much more quickly than just having a solid sheet of metal radiating heat out. There are all kinds of examples of objects designed to shed heat quickly through radiation try to get as much surface area as possible.


As far as rigidity read the wiki on how the calculations are made. Im not an engineer or mathematician so Im not going to attempt to measure barrels and test them to give you an exact answer... http://en.wikipedia.org/wiki/Second_moment_of_area



What Im NOT saying is fluting or dimpling strengthens are barrel. That is not true. The only thing doing that does is weaken it, increase heat transfer, and reduce weight. Weight reduction can improve the balance on certain setups.


Where fluting and dimpling comes into play is if you said 'I want to make this gun with a barrel that weighs no more than 2lbs'...a fluted or dimpled barrel that weighs 2lbs is going to be stiffer and have better heat transfer than a barrel that weighs 2lbs with no fluting or dimpling.

Just like a car radiator with fins that weighs 10lbs is going to have better heat transfer rates than a radiator without fins that weighs 10lbs where the heat transfer surfaces are just flat sheets of metal.